The present invention relates more particularly to a rear-view device for a land motor vehicle including: a reflective element forming a mirror which allows a main user to observe a zone situated to the rear of the rear-view device, and an illuminated display system comprising at least a first light source and at least an optical device allowing orientation of the light beam produced by the source in a determined direction orientated towards the rear and situated outside the field of view of the main user (the driver) in order to display at least a first illuminated signal in the rear-view zone, the said first illuminated signal being intended to be seen by other observers than the main user (drivers of other vehicles).
Such a type of device is described for example in the document U.S. Pat. No. 5,436,741. In this document, the mirror is mounted by its front face on a support which is provided with a housing containing a filament lamp. The mirror is partially transmissive and includes on its front face, opposite the housing, a transparent plate provided with a holographic element solely intended to orientate and control the angle of divergence of the light rays emitted by the lamp with a defined divergence.
This device has certain disadvantages. In fact, the illuminated display system is relatively bulky and it only produces a relatively blurred illuminated signal. Moreover, it requires the use of a partially transmissive mirror which on the one hand increases the cost of the mirror and degrades the “rear-view” function, and on the other increases the energy consumption due to the loss due to the partial transmissivity of the mirror. Also, the fact that the mirror must be semi-reflective in the display zone means that, in case of accumulation of dust on the surface of the mirror, the brightness will be reduced and in certain cases the signal will be invisible.
It should also be noted that in the prior art two types of signal were envisaged: absence of signal form (in this case the function is reduced to the lighting of a zone in the rear-view mirror without any form: arrow or other) with a limitation linked to the need to position the light source in a precise location of the rear-view mirror, and a light guide drawing the form of the signal (arrow, triangle or other) with an assembly of a plurality of light sources. This constitutes a major limitation as a guide must correspond to each symbol and therefore for a plurality of symbols there must be a sufficient capacity to incorporate the guides at distinct locations which is very difficult and requires a capacity much greater than the capacity available in a rear-view mirror, in addition to the need to have a plurality of light sources involving a high level of electrical consumption and a problem of heat dissipation.